Lapping machine



March 9, 1937. F. J. THELER ET AL 2,073,079

LAPPING MACHINE Filed July 15, 1952 L 4 Sheets-Sheet 2 Patented Marc 9,1&3?

UNITED STATES LAPPIN G MACHINE Frederick J. Theler, Cincinnati, GeorgeV. Johnston, Loveland, and Willetts Peaslee, Cincinnati, Ohio, assignorstov Cincinnati Grinders Incorporated, Cincinnati, Ohio, a corporation ofOhio Application July 15, 1932, Serial No. 622,662

15 Claims.

A further object of the invention is the provision of a lapping machinehaving universal adjustment whereby all sizes of work pieces within therange of. the machine may be expeditiously produced. v

Other objects and advantages of the present invention should be readilyapparent by reference to the following specification considered inconjunction with the accompanying drawings, forming a part thereof, andit is to be understood that any modifications may be made in the exactstructural details there shown and described within the scope of theappended claims, without departing from or exceeding the spirit of theinvention.

In the drawings:

Figure 1 is a front elevationof a machine em bodying" the principles uof this invention.

Figure 2 is an end elevation thereof as seen from the left hand side inFigure 1.

Figure 3 is a top plan view of the machine shown in Figures 1 and 2. t

Figure 4 is a fragmentary longitudinal sectional view as seen along line4-4 on Figure 3.

Figure 5 is a transverse sectional view as seen along line 5-5 on Figure1.

Figure 6 is a sectional view taken on line 66 of Figure 5.

Figure 7 is a sectional view similar to Figure 5 showing a modifiedstructure for performing the invention.

Figure 8 is a sectional view taken on line 88 mounted on any suitabletype of support, such as the bed ill which has formed on its uppersurface at opposite ends the guides H and I2 being received incorrespondingly shaped guideways l3 formed in heads or slides l4 and I5mounted respectively at the left and right hand sides of the bed It, asviewed in Figure 1. The head l5 may be conveniently termed the workcontrol head while the head I is the operating head and since the headsare substantially duplicates of one another it is deemed suflicient ifin the main but one of them be described in detail.

Accordingly, the head l4 has secured therein against rotation andindependent axial movement, a nut 16 in threaded engagement with anadjusting screw I7 rotatably journaled against axial movement inabearing l8 secured to the extreme end of the guide II. The screw I1projects beyond the bearing l8 and'has secured thereto a hand'or pilot.wheel l9.whereby said screw is rotated for effecting the adjustment ofthe slide or bracket l4 relative to the way II.

The head It, at its forward end, is provided with a face plate 20against which is butted an oscillatable or tiltable carrier 2| (Figure4) which includes journal bearings 22 and 23 (Figure 3); The carrier 2|is oscillatably mounted on the bearing portion 24 of a trunnion I00carried by the face plate 20 of the head. H. The wall or face plate 20of the head is provided with a plurality of elongated arcuate slots 25,26 and 2! (Figure 2) through which respectively extend clamping bolts28, 29 and 30. The bolts 28 and 303 respectively enter the base of thetrunnion v.

bearings 22 and 23, while the bolt 29 is received in a threaded holeformed in a flange 3| formed along the upper end of the carrier 2|. Fromthe foregoing it will be noted that the carrier 2| may be oscillatedrelative to the face plate 20 or adjusted about the axis of trunnion 24and clamped in said oscillated or adjusted position by-means of thebolts 28, 29 and 30. In order to minutely oscillatably adjust the saidcarrier, the face plate 20 has projecting from its rear surface a lug orear 32 (Figure 2) having formed therethrough a threaded, hole into whichan adjusting bolt 33 is threaded having its one end abutting a collar orroller 34' 'carried by the stud or bolt 28. To determine the amount ofoscillation given to the carrier 2| it has formed on or secured to theend thereof a pointer or zero mark "H, see Figure 1, which co-operateswith suitable graduations I02 carried by the adjacent end of the slideface plate 20.

Extending through the carrier journal bearlugs 22 and 28 is a'shaft orspindle 88 (Figures 1 and 4) to which is secured a comparatively longroll or drum 88 (Figure 5) adapted to rotate with the shaft and adaptedto have its axis 45 disposed at an angle depending upon the adjustmentof the carrier 2| around the axis of the trunnion 24.

The head I! is likewise provided with a face plate 81 (Figures 1 and 3)against which is butted 1 a carrier 88 having integral therewith thejournal bearings 88 and 48. Rotatably mounted in the Journal bearings 88and 48 is a spindle or shaft 4| to which is secured for rotationtherewith a roller drum 42 (Figures 1 and 4). The

15 carrier 88 and parts carried thereby are adapted to be oscillated oradjusted about a trunnion secured in the bracket or slide I! whichtrunnion is similar to the trunnion Hill of the slide or head l4. Theperipheries of the rolls or drums 86 and 42 are spaced from one anotherto form a work receiving throat through which the work I 88 passes whilebeing operated upon.

In order to rotate the shafts or spindles 88 and 4| they are eachrespectively provided on one end with a sprocket 48 or 44 about which isextended a sprocket chain 45. The sprocket chain is also trained aboutan idler sprocket 48 rotatably Journaled cm a stud 41 secured in the 20bed It, at a pointsubstantially midway between the sprockets 48 and 44near the base thereof as well as about a second idler sprocket 48rotatably journaled on a stud 48 projecting from the bed III to one sideof the stud 41. The chain 45 is further passed around the drivensprocket 88 keyed or otherwise secured to one end of a countershaft 8irotatably Journaled in the walls of the bed It. The countershaft 5| alsocarries a sheave 52 having a plurality of V-shaped grooves therein eachreceiving a V-type belt 58 which belts are inturn trained about adrivingsheave 54 secured in any desirable manner to the motor shaft I! oftheelectrical motor or prime mover 88 secured to one end of the bed It.

From the foregoing it will be noted that the drums 88 and 42 aresimultaneously rotated in the same direction from a single source ofpower such as the motor I8 (Figure 1). It should also be noted that thesprockets 48 and 44 are of slightly different diameters so that a slightdifferential in rotation between the drums 88 and 42 is had. Further,the direction of rotation of the drums is such that the proximate pointsthereof, which form the work receiving throat,

rotate or move in opposite directions, namely,

"" the face or periphery of drum 42 in theithroat travels upwardly asindicated by the arrow associatedtherewith in Figure 1 while the theretoopposed periphery of the drum 88 travels downwardly, again as indicatedby the arrow asso- 60 ciated therewith.

Work pieces produced by this machine must not only have the surfacethereof smooth and devoid of scratches'and grooves, but must be heldcircular from end to and within very narrow limits. Therefore, in orderto maintain the parts in ad- Justed positions and prevent deflectionthereof during operation, the face plates 20 and 81 have extendingbetween them a pair of tie rods 51 and 58 (Figure 3) being respectivelypositioned at 70 the rear and forward sides or ends thereof. As seen inFigure 3, the tie, bars 51 and 58 each have one of their ends securedrespectively at 58 and 68 in the face plate 81 and have their other endsextending through the face plate 28, which ex- 75 tending ends arethreaded to receive nuts SI and 82, each nut provided with handles 84whereby it may be readily rotated or adjusted. The face plate 20adjacent each of the nuts 6i and 62 is provided with a pointer 64(Figure 1)' which overlies the nut forco-operating with graduations 65placed around the exterior of the nuts adjacent the face plate 28. Inthe operation of the machine, if it is found that the pins do not feedthrough the work throat at a uniform rate, or one end of the throatpinches the work more than the other, the proper nut 8| or 82 isactuated to .either reduce or enlarge that end of the work receivingthroat.

As shown in the drawings and because of the tiltable carriers 2| and 88as above described,. the drums 88 and 42 are adapted to have their axesdisposed at an angle to one another and each has its' axis disposed atan angle to the horizontal plane of the machine. The drum 42 of 'thework control head has its axis disposed at a relativelyslight angle tothe horizontal extending upwardly from right to left, as seen in Figure5, or having its axis disposed at an angle extending upwardly from therear toward the front end of the machine, the direction of extent ofthis angle being such as to automatically feed work pieces from thefront or entrance side of the machine to the discharge or rear thereof.The drum 36 of the operating head has its axis disposed at a muchsteeper angle than the axis of the drum 42 and in an opposite direction,or extending upwardly from left to right, as seen in Figure 5, orextending upwardly from the front end toward the rear end of themachine. This roll or drum provides the finish on the work as it isaxially fed by the control roll or drum 42.

As shown in Figure 4 in connection with one embodiment of the mechanicalfeatures of our invention, the axis of. the work I08 is disposed abovethe plane or. line joining the axes of the rolls at the points where theaxes of said rolls cross each other when viewed, for example, from theleft-hand end of the apparatus as seen in Figure 1, which as shown inFigure 5, is substantially midway of the length of the rolls. In

other words and as is later more fully described and for reasons laterherein set forth in .greater detail, the line through which or the pathof travel along which the axis of the work is moved (from left to rightin Figure 5) is above any line joining the axes of the opposed rollsordrums 86 and 42. The proximate points of the said rolls are spacedfrom one another a suitable distance to provide this relationship, whichdistance is less than the diameter of the work and represents the pointor points above the point where the roll 86 tends to pull the workdownwardly through the throat, as viewed in Figure 4, for thereby, as islater explained in greater detail, we are enabled to gain certainadvantages flowing from the fact that the work pieces, throughout theirentire travel from left to right, as viewed in Figure 5, are supportedby the two rolls or drums 42 and 8B and from the fact that thereby wemay dispense with a separate work carrier or support underneath the workpieces; in Figures 4 and 5 it will be noted that the space immediatelyunderneath the work pieces I08, throughout the region in between theoperating member 88 and the control member 42, is devoid of means forsupporting the work pieces 'along their lowermosr. faces. All of this ismore clearly described hereinafter.

In order to maintain proper contact between the periphery of said rollsor wheels 38 and 42 and work I03, the bed I has secured to itsubstantially midway of its length and at opposite ends of the grindingthroat, posts 86 and 81 (Figure having their upper ends bifurcated orforked to provide arms 58 and 69 (Figure 6). Near the lower ends of thearms 08 and 99 they are provided in alignment with one another withslots 10 and 1I through which extends clamp bolts 12 for securing inadjustable position a block 13 having a trough 14 formed at the upperend thereof. The trough 14 is faced with soft rubber, felt or othermaterial to avoid scratching or marring of the work as it is introducedinto.

the machine. Trough 14 is positioned or alined with respect to the facesof the rotary members 42 and 36, the latter being trued or shaped ashereinafter described, to introduce the work pieces I03 (see Figure 5)in between these two members to be supported thereby and operated upon.The post 61'carries a similar mechanism including a block similar toblock 13 for providing a discharge trough or chute 15 (Figure 5),likewise faced with soft, non-scratching material receiving the workfrom the throat. Trough 7 as already above pointed out, the work I03can- 15 is also appropriately alined with respect to the operative facesof the members 30 and 42 at the right-hand end thereof, as viewed inFigure 5, in order to receive the work pieces from these members andvirtually to form an alined continuation of the support for the workpieces I03 formed by the rotary members 36 and 42 themselves, in thisembodiment or form of their invention. I

Near the upperends of the arms 68 and 69 they support a pin 16 (Figures5 and 6) which passes through an elongated slot 11 formed in lugs 18 and19 projecting from opposite ends'of a pressure shoe 80. The pressureshoe 80 has secured to its lower end a soft rubber, felt or othernon-scratching contact strip 8| (Figures 5 and 6) which bears on theupper surface of the work to hold it in contact with the peripheries ofthe drums 36 and 42. The pressure shoe 80 (see Figure 3) contacts withthe work or work pieces I03 and tends to force or hold them downwardly(see Figure 4) but because the proximate points of the rotary members 36and 42 are spaced from one another by a distance which is less than thediameter of the work $03,

not drop downwardly, as viewed in' Figure 4, nor can the pressure shoe80 cause the work to be forced downwardly and hence out of the operatingthroat and into the ab0ve-mentioned free space immediately underneaththe work I03 (see Figure 4). The pressure shoe 80 is held in contactwith the work by gravity only and is weighted in any suitable manner tovary the pressure on the work. In order to vary this pressure, and hencethe pressure of contact between'the work and the rotary members 42 and36, the shoe has projecting upwardly from it a pair of'studs 82 and 83(Figure 5) adapted to receive weights such as 84 which may be one ormore in number depending on the necessary or desired pressure to be hadon the work.

The surface on the work is produced by the coaction with the abovedescribed parts of a circulating abrading material which may be anyknown lapping compound in which a liquid and a fine abradant materialare employed.- The abradant material and liquid are thoroughly agitatedto insure the proper suspension in the liq'- uid of the abradantmaterial, which is circulated by a suitable pump 85 (Figure 1) securedto the rear end of the bed I0 and driven by multiple V-belts or the like88 which extend in turn about an extension of the sheave 52 on the countershaft 5i and a sheave 81 associated with the pump 85. Extendingfromthe pump 85 is a flexible hose or conduit 88 which terminates in a valve89 carried by a bracket 90 secured to the head I5. Extending from theother side of the valve 89 is a pipe 9| terminating, as shown in Figures3 and 5, in a T 92 from which branch,

distributor pipes 93 and 94 extend, the latter terminating in caps 95and 98. The branch distributor pipes are each provided with a pluralityof holes or slits 91 through which the abrading material flows againstthe side of the pressure shoe for distribution along the drum 38.

To limit the ultimate drop of the pressure shoe 80, as when there is nowork in the throat, the

lugs 18 and 19 have threaded into them stop,

bolts 98- and 99, respectively, adapted to engage with the pins 10.Suitable lock nuts are associated with the bolts for locking them inadjusted positions. When desired to grind different diameters of work,the bolts 98 and 99 are adjusted to=- properly position the wear strip8| relative to the axis of the work. I r

The lapping compound is normally contained in a. tank or sump J04, showndiagrammatically in Figure 9, disposed within the bed I0 from which itis drawn by the pump 85 through a suction pipe I05. In order to keep thelapping compound thoroughly mixed the. pipe or conduit 88 has extendingfrom it a conduit I06 in which is placed a relief valve I01 connected bya pipe I08 to the tank or sump I04. The pump-85 has a capacity greatlyin excess of the amount of lapping compound needed orcapable of beingdischarged through the orifices 91 in the branch distributor pipes 93and 94 so that a large amount of the lapping compound is returned to thetank or sump I04 through the relief valve I01 at such a speed and insuch quantities that it constantly agitates the material therein. The

compound actually dicharged through'thedistributor pipes 93 and 94 iscollected on a suitable drain board provided in the machine(diagrammatically indicated in Figure 9compare Fig. ures 5 and 7) forreturning same to the sump or tank by way of the conduit I09 connectedat opposite ends with the drain board and conduit I08.

In the modification shown in Figures land 8, the

pressure shoe H0 is supported in the same manner as disclosed in Figure5 and described above. The pressure shoe, however, does, not carry ayieldable or soft wear strip, but instead has formed adjacent the ears18 and 19 lugs III and.

plying the desired pressure on the work tomaintain the proper contactwith the wheels.

In; the embodiment shown in Figure 10 the mechanism is shown with theproximate portions of the wheels spaced further from one another so thatthe work piece, instead of being entirely supported bythe wheels as inthe embodiment above described in connection with Figures 4, 5 and 6,may be supported on a work rest blade H1 or the like. This work restblade H1 either is made of some relatively non-scratching material or isprovided with a strip or surface, as shown at I I8 in Figure 10,, madeof such a non-scratching material. In this construction the operating orlapping member is tilted at the same relatively steep angle as was abovedescribed while the control or feed member is tilted at the opposite butvery slight angle.

In ordinary grinding machines the axis of the work is disposed in aplane parallel with the plane of the axis of the g'rinding wheel orparallel with the abrasive periphery of the wheel so that a line contactis had between the wheel and work parallel with the axis of the work.Any vibraticnor lateral movement of either the work or the wheel causesthe wheel to dig into the work and thereby results in work having ridgesand valleys extending the full length of the work and around it so thata smooth surface is not formed thereon. These ridges and valleysconstitute what is commercially known as chatterw on the work, whichwhen the work is placed in use results in relatively rapid wearing .ofthe part until the ridges are completely removed.

By the use of this machine and with the'operating or lapping memberdisposed with its axis at a relatively steep angle to the axis of thework, the direction of motion of the surface of the lapping member, thisbeing the direction in which the finely divided abradant material of thelapping compound is made effective upon the work, is oblique to the lineof contact between the periphery of the member and the surface of X thework, whereby the operating or lapping member simultaneously engages thetops of a pluralityof ridges and operates upon the latter obliquely tothe line of contact between the work and member. In other words, theline of movement of a point on the lapping member to traverse that pointacross the line of contact of the member with the work is not at anangle of 90 degrees to the axis of the work, but is obliquely disposedrelative thereto whereby the above-mentioned point on the lappingmember, which point may be considered to be an abrasive particle,actually contacts with and obliquely absolutely devoid of any chatter.

traverses the tops of the ridges between a pair of the valleys andthereby insures the reduction of said ridges -to thelevel of thevalleys, and results in work pieces having a smooth surface By thisaction, therefore, no abrasive particle or point on the lapping membercan move in a path to carry it clear through a valley, but it mustobliquely traverse a ridge and thereby must do its share of the work inreducing that ridge.

It will be noted that in the mechanism illustrated in Figures 1 to 8,inclusive, and as already set forth above, there is no work support ofany type and that the work pieces are solely supported by theperipheries of the opposed operating and control members. By thisconstruction no imperfections in the supporting member or members dueeither to being non-parallel or out of alignment or for any other causeare transferred to the work since the work is influenced only by and isunder control of the opposed members which have their peripheries truedor shaped to the necessary and desired form. In certain circumstancesthe operative surfaces of either or both of these opposed members may beslightly concaved so that either or both members contact the work piecethroughout its length. The

concave shapes of the members 42 and 40 are indicated in the drawings,the operating or lapping member 36 being tilted at a greater angle andhaving a somewhat greater degree of concavity than that of theregulating member 42. Furthermore, by supporting the work on theperipheries of the wheels, no scratches are imparted to the work aswould be the case if a relatively hard supporting blade or the like wereprovided, which would also be subject to considerable wear, as is wellknown in standard commercial centerless grinding practice. In order tomaintain proper pressure of contact between the work and the peripheriesof the operating and control members at the respective and opposed linesof tangency or of contact of the latter with the work, the overheadpressure shoe, above de-.

scribed, is provided. By the use of the soft rubber or felt contactstrip with either the overhead pressure shoe or work supporting bladesuch as that shown in Figure 10, the abrasive grains and particles whichare carried by the work during its rotation, are wiped off or embeddedin the surface thereof. In other words, the soft pressure shoe yieldsand allows any abrasive grains that are carried thereto by the work toembed themselves therein so that the grains do not dig into the work andscratch or mar the surface thereof. This is of substantial advantageandthe results are preferable to those achieved if a relativelynon-yielding pressure shoe or supporting strip were employed withoutsome provision against the action of abrasive grains, for such anonyielding pressure shoe or support might act as of a proper fiatlapped finish on the work. In

elling at about 410 peripheral feet a minute, the

best results are obtained. This ratio produces a very fiat (smooth ordevoid of grooves and ridges) lapped finish and as the ratio isincreased.

the finish producedapproaches a grinding finish, which as is well knownis composed of alternate grooves and ridges, but due to the angle of theoperating member the grooves and ridges are not formed circumferentiallyof the work, as is usual grinding practice as above described, but areformed diagonally thereof. In other words, the nearer the ratio betweenthe peripheral speed of the wheel and work approaches 1 to 1, theflatter and finer the finish, while the greater this ratio becomes, thenearer the finish approaches a grinding finish. It being understood, ofcourse. that the grit of the abrasive grains must be within a certainrange of fineness to obtain these results.

In the operation of the machine illustrated in the drawings, theabrasive material circulated by the pump 85 is equally distributed bythe overhead pressure shoe along the periphery of the operating memberso that an equal action is ao'raovo had throughout the length thereof.It has fur ther been found that with the wheels properly aligned andtrued the overhead pressure shoe holds the work in contact with thewheels 5 throughout its length and with equal pressure, so that shouldthe work piece be slightly tapered the larger end thereof is heldagainst the members with greater force or under greater pressure untilit is reduced to substantially the same dilil ameter as the other orsmaller end whereby the machine in addition to providing a lapped finishon the work also produces work pieces that are round and straight fromend to end.

As is clear from the drawings and as is in- 1 dicated also above, thelapping, and controlling members are preferably of substantial axiallength, illustratively and preferably (see, for example, Figures 3, 5 or7) of an axial length in excess of their diameters; throughout thelength l of the controlling member 42 and along its line of contact withthe work piece or pieces I03. the member 42, due to' its tilt withrespect to the axis or path of travel of the work and hence due to theinclination between the path oi movement upwardly (Figure 1) of itsoperative surface with respect to the path of movement or axis of thework piece, steadily eifects a feeding movement of the work pieces fromthe front or entrance side of the machine to the' discharge or rearthereof (left to right, as viewed in Figures 5 and 7) while the higherspeed member (member '36) performing the lapping action has, as

above described, such an opposite inclination or obliqueness between thegenerally downward (see Figure 1) movement of its operative sur face andthe path of travel or axis of the work piece that anypoint on the member36, such as an abrasive particle moves obliquely to the circumierentialridges and valleys (resulting from 40 the grinding of the. work prior tobeing sub jected to the operation of our apparatus) and at anobliqueness opposed to the direction of feeding or axial travel of thework I03, all while the latter is being rotated,'and thereby thereduction or levelling oil of the ridges is dependably and quicklyachieved. The action of the abrasive particles throughout the extent ofthe line of contact between the work and the lappingmerm ber 36 is thusmade to be eifective in a direction oblique to this line of contact andhence not parallel to the direction in which the grooves or valleysextend circumferentially about the work piece and as the work piece iscontinuously rotated and moved through the machine, the effect v issomewhat ,like wiping this obliqueness of action, opposed to thedirection of feed, continuously around the whole work piece in a mannerto cause abrasive particles to traverse (rather than to line up with)the ridges and valleys and hence to achieve a rapid and dependablereduction of high points on the work. This reduction takes place whetherthe high points are due to longitudinal chatters or circumferentialgrinding grooves, or scratches, or both.

From the foregoing it will, therefore, be noted that the machine of thisinvention is particularly advantageous in the production of finesurfaces on circular work pieces and that there has been provided amechanism that willrapidly, con tinuously and at a high rate ofproduction produce work pieces having a lapped surface or finishthereon, thereby materially reducing the cost ofmanufacture of such workpieces.

What is claimed is:

, 1. In a lapping machine of the class described the combination of abed, a pair of opposed peripherally operative controlling and lappingmembers adapted to be rotated at slightly dif ferent speeds, thecontrolling member having its axis disposed at an angle to the intendedaxial 6 position of a work piece to be operated upon and extending in agiven direction, the lapping member having its axis disposed at agreater opposite angle than that of the controlling member, meanssupporting one of said members for ad- 10 justment toward and away fromthe other to space the proximate portions of the peripheries thereof adistance less at all points than the diameter of the work to be operatedupon, said members engaging the work in respective 1 lines of contactspaced apart by a distance substantially equal to the diameter of thework and lying in a plane above said proximate portions of theperipheries of said members, and pressure means having a non-scratchingcontact strip 20 above the work for engagement with the work to-hold thesame in contact with the peripheries of said members, means carried bythe bed adjacent the ends of said members for supporting the pressuremember, means operatively related 25 to the pressure means for varyingthe pressure thereof on the work, meanscarried by one of said pressuremember supporting means for supplying unfinished work to said members,and means carried by the other of said pressure member 30 supportingmeans for receiving the work from said members.

2. In a lapping machine of the class described the combination of a bed,a work head and control head mounted on opposite ends of the bed, 35

means adjacent each end of the bed for actuating the heads toward andfrom one another to position same, a rotating control member carried bythe control head and operable at a given rate of speed, a lapping memberrotatably carried by 40 the operating head and operable at a speedslightly in excess of the speed oi the control member, the adjustingmeans 01' said heads being adapted to position the members a distanceapart less than the diameter of the work to be operated 45 upon, a postat each end of the control and opcrating members, a pressure membersupported by the posts for contact with the work to hold same inengagement with the control and operating members, a non-scratchingcontact surface 60 between the work and pressure member, and meanscarried by the posts for supplying work pieces to the members andreceiving same therefrom.

a 3. In a lapping machine of the class described 55 the combination of abed, a work head and control head mounted on opposite ends of the bed,means adjacent each end of the bed for actuating the heads toward andfrom one another to position same,,a rotating control member carried 60by the control head and operable at a given rate of speed, a lappingmember rotatably carried by the operating head and operable at a speedslightly in excess of the speed of the control member, the adjustingmeans of said heads being adapted as to position the members a distanceapart less than the diameter of the work to be operated upon, a post ateach end of the control and opcrating .members, a pressure membersupported by the posts for contact with the work to hold 70 same inengagement with the control and oper-v means securing the control andoperating members to their respective heads for tilting adjustmentrelative thereto whereby the axes of the members may be disposed at anangle to one an- 6 other and to the bed.

4. In a lapping machine of the class described the combination of a bed,a work head and control head mounted on opposite ends of the bed, meansadjacent each end of the bed for actu- 10 ating the heads toward andfrom one another to position same, arotating control member carried bythe control head and operable at'a given rate of speed, a lapping memberrotatably carried by the operating head and operable at a speed slightlyin excess of the speed of the control member, the adjusting means ofsaid heads being adapted to position the members a distance apart lessthan the diameter of the work to be operated upon, a post at each end ofthe control and operating members, a pressure member supported by theposts for contact with the work to hold same in engagement with thecontrol and operating members, a non-scratching contact surface betweenthe work and pressure member, means carried by the posts for supplyingwork pieces to the members and receiving same therefrom, means securingthe control and operating members to" regulating wheel, a lapping wheelhaving extremely fine grit, a member against which the article to belappedmay rest in a position between said wheels and in contact with theperiphcries of both of thesame, means driving said' regulating wheel ata rate whereby it positively rotates said article at a predeterminedspeed, means adapted to guide a series of articles to be lapped to saidposition, means mounting said lapping wheel in a position in-which itsactive tion inclined with respect to the axis thereof, means adapted todrive said lapping wheel in a direction of rotation about its axissubstantially the same as that of said regulating wheel and,

at a surface speed which exceeds the surface speed of the article uponwhich it operates byan amount which is below the effective cutting speedof a grinding wheel, means adapted to vary the angular position of saidregulating wheel with respect to the path of the article and therebyvary the rate of feed of the article, and means adapted to adjustindependently the angle between said path and said lapping wheel to varythe angle of travel of the lapping surface with respect to the directionof travel of the surface of the article which it contacts.

6. In apparatus, for lapping the surface of articles of round.cross-section having elongated ridges extending lengthwise along itssurface, in combination, a regulating wheel, a lapping wheel havingextremely fine grit adapted to act upon the surface of the article to'be lapped without substantial reduction in size thereof, a'member alongwhich articles to belapped may travel axially in'a series into and outof position between and in contact with the peripheries of said wheels,said regulating wheel being driven at such rate as positively to rotatesaid articles in accordance with its surface speed and being adapted tofeed said articles in an axial direction, and said lapsurface will moveacross said article in a direcping wheel being mounted with its activesurface moving in a direction inclined with respect to the axis of saidarticles, and means driving said lapping wheel in a direction ofrotation about its axis substantially the same as that of saidregulating wheel and at a surface speed which exceeds the surface speedof the article being acted upon by an amount which is below and onlyafraction of the effective cutting speed oi a grinding wheel, the lineof' contact between said lapping wheel and said article extendingcircumferentially about said articleto bridge a plurality of saidridges.-

7. In apparatus for lapping the surface of articles of roundcross-section having elongated ridges extending lengthwise along itssurface, in combination, a regulating wheel, a lapping wheel having finegrit, said wheels bein adapted to receive a cylindrical articletherebefween in contact with the peripheries of both of them and saidlapping wheel having its active'surface moving in a direction inclinedwith respect to the axis of said article, means driving said'regulatingwheel at such rate and direction as to causeit positively to rotateand-feed said article, means driving said" lapping wheel in a directionof rotation about its axis the same as that of said regulating wheelandat a surface speed exceeding the surface speed of the article-beingoperated-upon by an amount which is below the eflective cutting speed ofa grinding wheel, the length of said wheels in the direction of the axisof said articles being sufficient to causethe line 'of; contact of saidlapping wheel with said article to extend circumferentially about saidarticles to a substantial ex tent and to bridge a plurality of saidridges, means adapted to adjust the angle of said regulating wheel tovary the rate of feed of the article, and means adapted to adjustindependently the angle at which the active lapping surface travels withrespect to the article.

8. In apparatus for lapping the surface of articles of roundcross-section, in combination, a

guiding member along which articles to be lapped substantially the sameas that of said regulating wheel and at a surface speed which exceedsthe surface speed of the article upon which it operates by a speed belowthe effective cutting speed of a grinding wheel, both of said wheelsbeing elongated with respect to their diameter and being oppositelyinclined with respect to the path of travel of the article, and meansadapted indeadapted to engage said article with its periphery aoraoro 1contacts by a speed which is below the effective cutting speed of agrinding wheel, the lncllnaticn of said lapping wheel with respect tothe article being such that its line of contact therewith will extendcircumferentlally about the article to 15 bridge a plurality of saidridges. and means 20 articles of round cross-section, in combination, a

guiding member along which articles to be lapped may travel, aregulating wheel mounted at one side of said guiding member with itsaxis inclined thereto and driven at such speed as to 5 positively rotateand feed with its periphery in an cndwise direction the articles to belapped, a lapping wheel having extremely fine grit opposed tosaid'regulating wheel and adapted to operate upon the surface of saidarticles with its periphery in a predetermined and substantiallyconstant direction oblique to the axis thereof, means adaptedindependently to adjust the angles of each of said wheels relative tothe path of travel of the article, and means driving said lapping wheelin a direction of rotation about its axis substantially the same as thatof said regulatingwhe'el at a surface speed which exceeds the surfacespeed of the article upon which it operates, the surface speedsof thelapping wheel and the article being lapped being closely approximateeach to the other and such as to alter substantially the direction ofthe path of contact of particles on the lapping wheel with the article,said path of contact being the vectorlal resultant of vectorsrepresenting respectively the speed and direction of movement of aparticle on the lapping wheel and the speed and direction of movement ofthat portion of the article engaged by the lapping wheel particle, andsaid resultant being at an angle of more than 20 and axis of thearticle.

11. In apparatus for lapping the surface of articles of roundcross-section having longitudinally extending ridges on its surface, incombination, a regulating wheel adapted to engage with its periphery andpositively to rotate the article to be lapped at a predetermined rate, alapping wheel having extremely fine grit adapted to engage said articlewith its periphery and mounted so as to cause its active surfacetotravel obliquely with respect to the directionof movement of the surfaceof the article which it con-- tacts, means adapted to guide a series ofarticles into said position between said wheels, and means driving saidlapping wheel in a direction of rotation about its axis substantiallythe same as that of said regulating wheel and a rate ofsurface speed inexcess of that of said article which is below and only a fraction of theeffective cutting speed of a grinding wheel, and is such as to causethepaths of contact of its particles with said article to besubstantially altered in direction by the movement of the surface ofsaid article, and the length of said wheels in the direction of the axisof said articles being 'sumcient to cause the line of contact of saidlapping wheel with saidv articles to' extend circumferentially aboutsaid articles to a substantial extent and to bridge over a plurality ofsaid ridges.

, 12. In apparatus for lapping the surface of articles of roundcross-section, in combination, a regulating wheel adapted to engage withits periphery and positively to rotate the article to be lapped at apredetermined rate, said regulating wheel being arranged with respect tothe axis of said article to efiect an axial feeding component thereon, alapping wheel having extremely fine grit adapted to engage with itsperiphery said article and mounted so as to cause its active surface totravel obliquely with respect to the direction of movement of thesurface of the article which it contacts, each ofsaid wheels having anactive surface longer than the diameter thereof, means adapted to swingone of said wheels in a. horizontal plane relative to the other, meansadapted to guide a series of articles into said position between saidwheels, and means driving said lapping wheel ina direction of rotationabout its axis the same as that of said regulating wheel and at a rateof surface speed relative to that of the work and in excess of that ofthe article and so far below the efl'ective cutting speed of a grindingwheel as to cause the paths of contact of its particles with saidarticle to be substantially altered in direction by the movement of thesurface of said article, the line of contact between said lapping wheeland said article extending circumferentially about the article to asubstantial extent. v

13. The art of lapping the surface of articles having elongated ridgesthereon which consists in passing said articles in succession into andout of a. position between a regulating wheel and a. lapping wheel theactive particles of which lapping wheel are greatly finer than the widthof said ridges, said articles in said position being in engagement withsaid regulating wheel and also with said lapping wheel along. a helicalline which bridges a plurality of said ridges, rotating said regulatingwheelat such rate as will cause it to govern the rotation of an articlein contact therewith, and simultaneously moving the active surface ofsaid lapping wheel relatively to the surface of said article in adirection substantially opposite to that of the neighboring surface ofsaid regulating wheel and inclined with respect to said ridges, and thesurface speed of said'artlcle being substantially equal'to that of saidregulating wheel and being exceeded by the surface speed of said lappingwheel in contact therewith by an amount which is below and only afraction of the effective cutting speed of a grinding" wheel.

14. The art of lapping the surface of cylindrical articles whichconsists in feeding them endwise in series between and in contact withthe peripheries of a regulating wheel and a lapping wheel having anextremely fine abrasive surface, moving the surface of said regulatingwheel in such direction as to tend to feed said articles endwise and atsuch speed as to control and de- I termine the rate of rotation andrateof feed of said articles, rotating said lapping wheel in a direction ofrotation about its axis substantially the same as that of saidregulating wheel and at such surface direction and speed relative to thesurface speed of said article in contact therewith as will exceedthat'of said article and causethe path of contact of the particles ofsaid lapping wheel with said article to be distorted into a directionlying between 20 and 10 away from a plane transverse to the axis of thearticle by reason of the relatively substantial surface speed 01' thearticle.

15. The art of perfecting cylindrical articles by removing elongatedprojecting ridges from the surface thereot which consists in advancingsaid articles endwise at constant speed along a path in which theycontact the concave periphery of an abrasive member of fine grit along ahelical line which extends from end to end or the member and whichbridges a plurality of saidridges at an acute angle, rotating saidarticles at con-

